1. Technical Field
The disclosure relates to an internal combustion engine and a control method of an internal combustion engine.
2. Description of Related Art
Japanese Patent Application Publication No. 2011-214477 (JP 2011-214477 A) discloses an internal combustion engine including a characteristic switching mechanism that can switch a lift characteristic of an exhaust valve between a first lift characteristic in which the exhaust valve is opened in an exhaust stroke and a second lift characteristic in which the exhaust valve is opened in an exhaust stroke and an intake stroke. JP 2011-214477 A also discloses a controller for an internal combustion engine configured to switch the lift characteristic of the exhaust valve to the first lift characteristic in an operation range in which fuel is combusted by flame propagation combustion and to switch the lift characteristic of the exhaust valve to the second lift characteristic in an operation range in which fuel is combusted by pre-mixture compression ignition combustion. In JP 2011-214477 A, high-temperature exhaust gas discharged from a cylinder in an exhaust stroke is sucked back into the cylinder in a subsequent intake stroke by opening the exhaust valve again in the intake stroke in the operation range in which fuel is combusted by pre-mixture compression ignition combustion, and a cylinder temperature is increased to a temperature at which pre-mixture compression ignition combustion can be carried out.